Technical Field
The invention relates to a vibrating element, and particularly relates to a vibrating element adapted for a speaker unit.
Related Art
Along with development of technology, electronic products are developed towards a trend of miniaturization, and people can use the miniaturized electronic products, for example, radios, walkmans, etc., at anytime anywhere. Moreover, as personal digital products are gradually popularised, the commonly used MP3, mobile phones, personal digital assistants (PDAs) or notebooks, etc. become indispensable in daily life. Moreover, smart phones capable of providing various audio and video entertainments are more popular products.
Regardless of the type of the aforementioned electronic products, in order to facilitate a user hearing audio information provided by the electronic product without interrupting others, earphone becomes a necessary accessory of the electronic product. Moreover, the earphone also provides the user a better sound transmission, such that the user can clearly hear and learn the sound content unlike a situation of hearing unclear sound in case that the sound is transmitted through air, especially when the user is in a motion state, for example, doing sports, driving, conducting intense activities, or in a noisy environment.
In a speaker unit of a conventional earphone, circuit lines connected to two ends of a voice coil used for driving a diaphragm directly cross over the diaphragm and are connected to a signal source at periphery of the diaphragm. Moreover, the circuit lines are coated with a wire protection glue. Therefore, the voice coil crossing over the diaphragm severely influences vibration of the diaphragm, such that frequency response of the speaker unit is degraded, which leads to a poor sound quality performance.
FIG. 1 is a schematic diagram of a speaker unit in U.S. Patent Application No. US 2010/0183173. Referring to FIG. 1, the voice coil 20 is directly disposed on the diaphragm 10, and the voice coil 20 is electrically connected to a metallic surface 11 of the diaphragm 10. Two circuit lines 15 are attached to the edge of the diaphragm 10 and are electrically connected to the metallic surface 11. However, two ends 25 of the voice coil 20 are connected to the metallic surface 11 at the periphery of the voice coil 20. Since stiffness of connection points of the two ends 25 of the voice coil 20 is obviously different to that of the diaphragm 10, and the part of the diaphragm 10 at the periphery of the voice coil 20 is a main vibration area, which is required to be soft and have similar Young's modulus in order to vibrate in large amplitude and in consistency for providing a low frequency sound. However, the connection points of the two ends 25 of the voice coil 20 obviously spoil vibration consistency of such area, such that the distortion is increased and the sound quality if deteriorated.